1. Field of the Invention
This invention relates to an automatic original feeding apparatus and more particularly, to an automatic original feeding apparatus used in an image forming apparatus such as a copying apparatus or a recording apparatus having the image area designating function and provided with a digitizer (coordinates position detecting device) for reading the area of the original image.
2. Related Background Art
Heretofore, in copying apparatuses, an original has been placed onto an original supporting table (a platen) by hand, but placing a number of originals one by one onto the original supporting table has been inefficient and for this reason, it has become popular to mount on the copying apparatus an automatic original feeding apparatus for automatically feeding sheet originals onto the original supporting table and automatically discharging the sheet originals therefrom. Further, there are multifunction copying apparatuses endowed with the multiplex copying function of copying a plurality of originals on the same surface of a transfer medium, the multicolor copying function of using color (e.g., red, blue, etc) developing devices instead of the ordinary black developing device to obtain colored copy images, and the area designating function (or the coordinates position detecting function).
That is, the above-mentioned area designating function refers to selecting only the image of the necessary area from an original image and copying that image, and is such that when the desired image area is first measured in X and Y dimensions and the value thereof is input on an operating panel, a light-emitting element array provided near a photosensitive member for forming images emits light partly and time-serially in response to the signal to erase the electrostatic latent image of the unnecessary area on the photosensitive member, thereby obtaining the image of the necessary area.
Further, there is also a method of effecting area designation by the use of a digitizer (coordinates position detecting device). When utilizing this method, if an original is placed onto the digitizer and the necessary image area is pressed from above the original, that area is automatically detected and thus, the work of measuring the above-mentioned necessary area is not required.
A combination of the aforementioned multiplex copying function, multicolor copying function and area designating function may lead to achievement of a further multifunction. In the case of the previously mentioned multiplex copying, the plurality of originals have been different in locations of images and it has been necessary to choose the originals so that overlapping of copy images may not occur, but by the area designating function being added thereto, the image area in which overlapping will occur can be erased and it becomes unnecessary to choose the originals. Accordingly, the combination of these three functions enables a multiplex or multicolor image to be obtained from any original. Of course, it can be easily accomplished to erase the unnecessary area image for an original and obtain necessary-area, image as previously described.
A description will now be provided of a prior-art copying apparatus having the above-mentioned area designating function and provided with an automatic original feeding apparatus.
This copying apparatus, as shown in FIG. 1 of the accompanying drawings, has an automatic original feeding apparatus 2 on the upper portion of the apparatus body M and is provided with an area designating apparatus 3 constructed separately from the copying apparatus body M. In the area designating apparatus 3, a digitizer 6 is installed on the digitizer supporting table 5 thereof and a stylus pen 7 is disposed thereon, and an original P is placed on the digitizer 6 with the image bearing surface thereof facing upward and with the right end thereof being in contact with an original-striker (not shown) and the inner side thereof being in contact with the original-striker, not shown. A desired area of the image bearing surface of the original P is then pressed by the stylus pen 7, whereby said area is designated and input. Various inputting methods or detecting methods have been proposed, but they will not be described in detail herein. When the desired area is input, whether the image of the input desired area should be presented or a desired mode of color designation or the like is selected by a function key 9, and a signal input by the digitizer 6 and the function key 9 is transmitted to the copying apparatus body M through a signal line 10. The original P placed on the digitizer 6 of the area designating apparatus 3 with the desired area thereof designated and input is then transferred onto the original tray 11 of the automatic original feeding apparatus 2 disposed on the upper portion of the copying apparatus body M, and is moved on the original tray 11 with the image bearing surface thereof facing downward and with the right end thereof which is in contact with the original-striker being as the leading end, and is inserted to a predetermined striking position of the automatic original feeding apparatus 2. Thereupon, the automatic original feeding apparatus 2 is operated to feed the original P to the image forming station of the copying apparatus body M, and the copying apparatus M effects a predetermined copying operation.
However, the above-described prior-art copying apparatus M has the separate area designating apparatus 3 and therefore requires extra installation space for the area designating apparatus 3. Also, since the area designating apparatus 3 is constructed separately from the copying apparatus M, the operator must go through numerous procedures of operation. That is, there is an original-striking reference in the digitizer 6 and there is further an original-striking reference in the automatic original feeding apparatus 2 and thus, the operator must accurately bring the right end of the original which bears against the original-striking reference in the digitizer 6 into contact with the original-striking reference in the automatic original feeding apparatus 2, and further must change the image-bearing surface of the original P from its upwardly facing position to its downwardly facing position and transfer the original P onto the original tray 11. These operations are cumbersome to the operator. Also, when the operator effects a wrong area designation and must re-designate the area, the work doubles with great inconvenience.
In view of this, an automatic original feeding apparatus having a digitizer made integral therewith has been proposed by the applicant (U.S. Application Ser. No. 895,031 filed Aug. 8, 1986).
This automatic original feeding apparatus devised by the applicant will hereinafter be described.
The automatic original feeding apparatus 20 devised by the applicant is disposed on the upper portion of a copying apparatus M having the area designating function, as shown in FIG. 2 of the accompanying drawings. The automatic original feeding apparatus 20 has a whole-surface belt 22 in the substantially central portion thereof which faces the platen glass 21 of the copying apparatus M, and is provided with an inlet tray 23 for supporting sheet originals thereon at one end. A feed roller shaft 25 is provided near the tray 23, and a feed roller 26 is secured to the shaft 25 for rotation with the feed roller shaft 25. A paper feeding arm 27 has one end thereof rotatably supported on the feed roller shaft 25, and a pick-up roller 29 is rotatably supported on the other end of the paper feeding arm 27. The pick-up roller 29 is pivotable up and down with the paper feeding arm 27 with the feed roller shaft 25 as the fulcrum. The rotation of the feed roller 26 may be transmitted to the pick-up roller 29 through a gear, not shown, so that the feed roller 26 and the pick-up roller 29 may be identical with each other in the direction of rotation and the peripheral speed thereof. Further, a front paper feeding roller 30 is rotatably provided in face-to-face relationship with the pick-up roller 29, and a rear paper feeding roller 31 is rotatably disposed in face-to-face relationship with the feed roller 26. A pick-up arm 33 having one end thereof secured to a pick-up arm shaft 32 is provided near the paper feeding arm 27, and a slide groove 33a is formed in the other end of the pick-up arm 33. A pin 27a projectedly provided on the paper feeding arm 27 fits in the slide groove 33a, and when the pick-up arm shaft 32 is rotated, the pick-up arm 33 pivots, and as the pick-up arm 33 pivots, the pick-up roller 29 pivots up and down and comes into pressure contact with or away from the front paper feeding roller 30. When the pick-up roller 29 comes into pressure contact with the front paper feeding roller 30, these two rollers 29 and 30 feed a sheet original nipped therebetween. An original presence detecting sensor S.sub.1 which is a reflection type sensor is provided near the pick-up roller 29. On the other hand, a drive roller 35 and a turn roller 36 are disposed above the opposite ends of the platen glass 21, and the whole-surface belt 22 is passed over these two rollers 35 and 36. The whole-surface belt 22 is an endless belt having a sufficient width to cover the whole surface of a sheet original, and the surface thereof is coated with a rubber material having a sufficient coefficient of friction so as to be capable of conveying originals by the friction force thereof. The turn roller 36 is movable to the left and right, and it is biased leftwardly when the whole-surface belt 22 is passed thereover, and is designed such that the whole-surface belt 22 has sufficient tension and causes no slippage between it and the drive roller 35. Further, keep rollers 37a, 37b, 37c, . . . are provided inside the whole-surface belt 22, and these keep rollers 37a, 37b, 37c are disposed at a pitch somewhat narrower than the size of the sheet original being conveyed. Further, these keep rollers 37a, 37b, 37c urge the whole-surface belt 22 against the platen glass 21 with a weak pressure force, thereby increasing the sheet original conveying force of the whole-surface belt 22. A pair of lower discharge rollers 39 and a pair of upper discharge rollers 40 are disposed near the turn roller 36 over which the whole-surface belt 22 is passed, and a discharge detecting sensor S.sub.2 is disposed in proximity to the pair of lower discharge rollers 39 to detect the discharge of a sheet original and to turn on a jam lamp when no sheet original is detected even if a predetermined time elapses. A pair of curved guides 41 for guiding the discharged original is provided between the pairs of upper and lower discharge rollers 40 and 39 so as to guide the discharged sheet original from the pair of lower discharge rollers 39 to the pair of upper discharge rollers 40. Further, a digitizer 42 is disposed above the whole-surface belt 22, and this digitizer 42 designates and inputs an area of the sheet original placed thereon with the image bearing surface thereof facing upward as previously described, by such means as a stylus pen. An original-striking reference 43 is secured in proximity to one end of the digitizer 42 which faces the drive roller 35, so that when a sheet original is placed on the digitizer 42, the right end of the sheet original may bear against the original-striking reference 43 and the inner side edge of the sheet original may bear against a striker, not shown, whereby the sheet original may be positioned. A pair of carrying-in sheet guides 45 is provided from the original-striking reference 43 to the platen glass 21 and further, a pair of carrying-in rollers 46 is disposed in the intermediate portion of the pair of carrying-in sheet guides 45, and an original carrying-in path 47 is formed by the pair of carrying-in sheet guides 45. An original carrying-in portion sensor S.sub.3 is disposed in face-to-face relationship with the upstream of the original carrying-in path 47, and a leading end detecting sensor S.sub.4 is disposed in face-to-face relationship with the lower end of the pair of carrying-in sheet guides 45.
Designated by reference numeral 49 below the platen glass 21 is the optical system of the copying apparatus M.
Now, the automatic original feeding apparatus 20 is effective in that it does not require any extra installation space for the area designating apparatus and eliminates the necessity of changing the image bearing surface of the original from its upwardly facing position to its downwardly facing position, but the original Pb after the termination of the area designating operation must be released from the original-striking reference 43 by the operator and fed into the nip between the pair of carrying-in rollers 46. The work of releasing the original Pb from the original-striking reference 43 and feeding it into the nip between the pair of carrying-in rollers 46 is cumbersome, and has led to the undesirable possibility that the striking side of the original is bent and the original is misconveyed or obliquely moved.